| 摘要 |
A prover includes a measurement cylinder; a hydraulic cylinder coupled with a side of a downstream end of the measurement cylinder; a measuring piston that moves through a predetermined distance from an upstream side toward a downstream side through the measurement cylinder to eject a reference volume of fluid; and a piston rod that is movably accommodated in the hydraulic cylinder, and has the measuring piston and the piston rod separately constructed. The prover includes measurement standby position stop means, and when returning the measuring piston to a predetermined measurement standby position, the piston rod moves the measuring piston from the downstream side to the upstream side and the measurement standby position stop means stops the measuring piston at the predetermined measurement standby position, after which only the piston rod is caused to move from the upstream side to the downstream side and is accommodated in the hydraulic cylinder. |
